Division (a) Minimum requirements for water quality
United Kingdom
Table 2 – Reclaimed water quality requirements for agricultural irrigation
| Reclaimed water quality class | Indicative technology target | Quality requirements | ||||
|---|---|---|---|---|---|---|
| E. coli(number/100 ml) | BOD5(mg/l) | TSS(mg/l) | Turbidity(NTU) | Other | ||
| A | Secondary treatment, filtration, and disinfection | ≤ 10 | ≤ 10 | ≤ 10 | ≤ 5 | Legionella spp.: < 1 000 cfu/l where there is a risk of aerosolisation Intestinal nematodes (helminth eggs): ≤ 1 egg/l for irrigation of pastures or forage |
| B | Secondary treatment, and disinfection | ≤ 100 | In accordance with Directive 91/271/EEC (Annex I, Table 1) | In accordance with Directive 91/271/EEC (Annex I, Table 1) | - | |
| C | Secondary treatment, and disinfection | ≤ 1 000 | - | |||
| D | Secondary treatment, and disinfection | ≤ 10 000 | - | |||
Reclaimed water shall be considered to be in compliance with the requirements set out in Table 2 where the measurements for that reclaimed water meet all of the following criteria:
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the indicated values for E. coli, Legionella spp. and intestinal nematodes are met in 90 % or more of the samples; none of the values of the samples exceed the maximum deviation limit of 1 log unit from the indicated value for E. coli and Legionella spp. and 100 % of the indicated value for intestinal nematodes;
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the indicated values for BOD5, TSS, and turbidity in Class A are met in 90 % or more of the samples; none of the values of the samples exceed the maximum deviation limit of 100 % of the indicated value.
Notes on Division
Footnotes
- f1
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If the same type of irrigated crop falls under multiple categories of Table 1, the requirements of the most stringent category shall apply.
- f2
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Drip irrigation (also called trickle irrigation) is a micro-irrigation system capable of delivering water drops or tiny streams to the plants and involves dripping water onto the soil or directly under its surface at very low rates (2–20 litres/hour) from a system of small-diameter plastic pipes fitted with outlets called emitters or drippers.
- f3
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In the case of irrigation methods which imitate rain, special attention should be paid to the protection of the health of workers or bystanders. For this purpose, appropriate preventive measures shall be applied.